"Stone Cold" Steve Austin's "WHAT?" during his 2001 heel run (WHAT?) definitely qualifies. He would say "WHAT?" (WHAT?) whenever someone tried to speak (WHAT?) during his promos as a way (WHAT?) to intimidate his opponent. However, it eventually caught on (WHAT?) with the fans (WHAT?), basically killing his heel push (WHAT?), and causing Austin to slowly revert to becoming a face again. (WHAT?) The audience would use the "WHAT?" chant (WHAT?) whenever someone tried the overdone style of "Short Statement Followed By Dramatic Pause" Promo Cutting.(WHAT?)
After a few weeks of frustration concerning tag partner Tajiri, Eddie Guerrero went berserk when Tajiri touched his low-rider (in reality, Tajiri had been thrown into the car by an opponent) and tossed Tajiri into the windshield. The next SmackDown, Eddie cut a promo saying that he was only going to look after number one, which was supposed to be a heel turn, but the fans had begun to buy into the Lie, Cheat, and Steal face persona cultivated just a few weeks prior with Los Guerreros' feud with Team Angle that the action fit the criteria, and the crowd cheered for Eddie. Suffice to say, Eddie stayed a babyface.
In WCW, there was the Heel faction, the West Texas Rednecks, who were fans of country music. They feuded against the hip-hop artist, Master P and the No Limit Soldiers, who were pushed as faces. Problem was, that WCW held their shows in the south, where rap music was hated. Not only that — Curt Hennig and company were charismatic wrestlers who deliberately acted funny, and had a catchy theme song, while Master P's crew were ebonics-spouting stereotypical thugs who drastically outnumbered their foes (thus coming across as bullies and the heels as brave victims). Because of this, the West Texas Rednecks were cheered by the Southern crowd, and their song, "Rap is Crap", actually received airtime on Country stations.
When Floyd Mayweather was booked to face The Big Show at Wrestlemania 24, he was originally projected as the face, supposedly putting his boxing career at risk against a much larger opponent. Most fans, however, hated Mayweather's showboating and were so glad to see Show come back from retirement that WWE had to quickly reverse the roles.
Ted DiBiase Jr. was supposed to be booked as the babyface during the Legacy breakup and have a singles push. WWE's build up was going to have Randy Orton be the heel with Ted being the popular babyface but Orton's antics made him so popular with the fans that it made him look like the face of the feud so WWE had to do a quick change and have Ted Jr remain heel. Edge even lampshaded this in a promo during his confrontation with Orton.
In the start of EV2's feud with Fortune the crowd was rooting for the stable Fortune, even during the beatdown that Fortune gave EV2, the night after EV2 had their reunion PPV, the crowd was chanting for Fortune. Spoony even commented that it's hard to root against Fortune because they were booked as a fun heel group, and was the kind of group that you might like to hang out with. It also made sense that the group, outside of Ric Flair, consists of a bunch of upcoming TNA superstars while EV2 consists of a bunch of people that are past their prime.
This is how the smark community works in general. Their basic rule is: You must love and cheer for the best pure technical wrestler, no matter how bad his character is made out to be. You get extra points if doing so wrecks one of WWE's live shows.
They'll also cheer a Heel if his persona happens to be very entertaining. The best example currently is The Miz, who, at best, could be considered decent in the ring, but his Troll character is so hilariously petty that Smarks just fell in love with the guy. Until WWE ran with it by giving him more screen time and putting the belt on him, at which point they turned and criticized his in-ring action again.
Similarly, the concept of "Indie darlings" and "Internet celebrities" leads to someone who should be either booed or laughed at ending up being cheered more than the rest of the promotion put together. Sometimes this forces the writers' hands, if only for a short while. Case in point? CM Punk, Daniel Bryan, Zack Ryder, the WWE, World Heavyweight and US champions at the same time. Woo, woo, woo! You know it! At least until Punk and Bryan were given a gradual (and believable) Face Heel Turns (Bryan's about a few weeks into his reign, Punk's in the middle of the summer) while Zack lost the belt to Jack Swagger, and stoppedwrestling on Raw or Smackdown.
It's well known in the WWE that it's really, really hard to get a Canadian audience to consider a Canadian wrestler as the heel in a given match unless they happen to be fighting another Canadian. WWE specifically renamed rising monster heelCanadian Earthquake (John Tenta) to simply Earthquake going into WrestleMania VI, which was held in Toronto.
In another example of the Canadian audience turning things topsy-turvy for bookers, when Hulk Hogan returned to WWE they were setting him up to continue his "Hollywood" Hulk Hogan heel persona and feuding with then-face The Rock. The only problem was that the climax of the feud took place at WrestleMania X8 in Toronto. Since WCW had rarely ventured north of the border, Canadian fans still largely remembered the classic face Hulk Hogan and proceeded to go completely wild over him, and booing The Rock, to the point where, by the end of the match, they had accomplished a completely unplanned Heel-Face Turn. You could hear the disbelief at the announcing table as this was going on.
That wasn't really a Canadian thing. The audience was starting to turn in favor of Hogan even before WrestleMania X8. The crowd exploded in cheers at the Raw event the week before when Hogan pinned Rock in an nWo vs Rock and Austin handicap tag match held in Detroit. It was really much more of a "Rock is getting stale" feeling coinciding with a huge nostalgia rush for Hogan and the nWo who hadn't been around for a few years.
Similarly, at WCW Mayhem 99, November 21, 1999, which was held in Toronto, the Canadian fans booed the FaceGoldberg and cheered the HeelSid Vicious, because of the WWE party line that Goldberg was a "Stone Cold" Steve Austin ripoff, and Sid was previously an on-and-off WWE guy.
This happens WAY more often then it should. At nWo Souled Out 97, a match between Masahiro Chono (Japanese) and Chris Jericho (Canadian) resulted in "USA!" chants. Eric Bischoff would lampshade this by saying something to the effect of "The fans know where they live."